1. Field of the Invention
This invention relates to a macro array for use in molecular biology research, such as genetic expression analysis, medical fields, and other fields.
2. Description of the Related Art
Conventional macro arrays comprise a membrane and a plurality of spots (dots), which contain biopolymers, such as DNA""s, and are arrayed (formed) on the membrane. With the macro arrays, multiple kinds of samples can be analyzed at one time on a single membrane. Therefore, the macro arrays are used widely in the molecular biology and the medical fields. For example, in cases where test substances are various kinds of genome DNA fragments, behavior of plurality of genes can be analyzed at one time by adding a probe, which has been prepared from total mRNA, or the like, onto the macro array and causing hybridization, or the like, to occur.
However, the conventional macro arrays are constituted by arraying spots, which contain test substances, such as DNA""s, in good order on a polymeric organic membrane formed from nitrocellulose, or the like. Ordinarily, porous polymeric films, such as the nitrocellulose membranes, are markedly soft and apt to suffer from bending and creasing, which adversely affects the analytic operations, and the like. Therefore, in cases where the conventional macro arrays are subjected to hybridization, autoradiography, and the like, the operator must process and carry the membranes, which constitute the macro arrays, with the greatest possible care.
The primary object of the present invention is to provide a macro array, wherein a film-shaped material, which is not apt to suffer from bending and creasing, is employed as a base material, such that the macro array is easy to process.
The present invention provides a macro array, comprising a film-shaped hard porous body and a plurality of spots, which contain test substances and are arrayed on the film-shaped hard porous body.
The macro array in accordance with the present invention will hereinbelow often referred to as the hard macro array.
The term xe2x80x9cfilm-shaped hard porous bodyxe2x80x9d as used herein means the porous body formed from an inorganic compound (which may be, for example, a metal type of compound) into a film-shaped shape (typically, a film-shaped shape having a film thickness of at most 2 mm).
Also, the term xe2x80x9cmacro arrayxe2x80x9d as used herein means the film-shaped body comprising the film-shaped hard porous body and a plurality of test substance-containing spots, which are arrayed (typically, in a matrix-like form) on the film-shaped hard porous body. Typically, the macro array may comprise the film-shaped hard porous body and a plurality of spots, which contain polynucleotide samples for genetic expression analysis, determination of a base sequence, variation analysis, polymorphism analysis, or the like, and which are arrayed on the film-shaped hard porous body. However, the purposes, for which the macro array in accordance with the present invention is used, are not limited to the applications described above. Specifically, the macro array in accordance with the present invention may comprise the film-shaped hard porous body and a plurality of spots of test substances, which may presumably contain substances (target substances) for the identification, analysis, or the like, of the target substances through chemical reactions or physical reactions, the spots being arrayed (typically, in a matrix-like form) on the film-shaped hard porous body.
Further, the term xe2x80x9ctest substancexe2x80x9d as used herein means the substance to be analyzed on the macro array through hybridization or other techniques. Typically, the test substances may be biopolymers (i.e., polymeric electrolytes of the types constituting living bodies), such as polynucleotides, e.g. DNA""s and RNA""s, chemically synthesized oligonucleotides, and peptides. However, the test substances are not limited to the substances enumerated above. Specifically, the test substances may be various polymers and various monomers, which are capable of being adsorbed or fixed to the film-shaped hard porous body. (The polymers and monomers may be capable of being fixed to the film-shaped hard porous body such that they do not separate easily from the film-shaped hard porous body.)
The term xe2x80x9cspotxe2x80x9d as used herein means the visually perceptible or visually imperceptible fine point on the film-shaped hard porous body, at which point the test substance, such as the biopolymer, is adsorbed or fixed.
In the hard macro array in accordance with the present invention, the base material, on which the test substance-containing spots are formed, is the film-shaped hard porous body. Therefore, the advantages over the conventional macro arrays, in which polymer types of porous membranes are utilized as the base materials, can be obtained in that the film-shaped hard porous body are not apt to suffer from bending and creasing as in the cases of the polymer types of porous membranes having a markedly high softness. Therefore, the operator need not pay close attention to the prevention of bending and creasing of the film-shaped hard porous body and is capable of more easily processing the hard macro array in accordance with the present invention than in the conventional macro arrays.
Also, with the hard macro array in accordance with the present invention, wherein the base material is constituted of the film-shaped hard porous body, when the test substance-containing sample is applied drop-wise (i.e., spotted) onto the film-shaped hard porous body, part of the test substance-containing sample is capable of permeating to the interior of the pore. Therefore, the test substance-containing sample having been spotted can be restricted from diffusing horizontally on the surface of the base material (i.e., the film-shaped hard porous body). As a result, the diameter of the spot formed on the surface of the base material can be kept small. Accordingly, with the hard macro array in accordance with the present invention, the comparatively small spots can be arrayed at a high density.
In the hard macro array in accordance with the present invention, the film-shaped hard porous body should preferably be constituted of a surface layer region, which is provided with through-pores having a comparatively small mean pore diameter, and a base layer region, which is provided with through-pores having a comparatively large mean pore diameter. The term xe2x80x9csurface layer regionxe2x80x9d as used herein means the surface layer region of the base material containing the surface on which the spots are formed and arrayed. The term xe2x80x9cbase layer regionxe2x80x9d as used herein means the layer region, which is adjacent to the surface layer region with respect to the direction of the film thickness of the film-shaped hard porous body. With the hard macro array in accordance with the present invention, wherein the film-shaped hard porous body is constituted of the surface layer region, which is provided with the through-pores having a comparatively small mean pore diameter, and the base layer region, which is provided with through-pores having the comparatively large mean pore diameter, the test substance applied onto the surface of the surface layer region is apt to remain on the surface of the surface layer region due to the comparatively small pore diameters of the pores in the surface layer region. Also, a solvent, such as water, which is contained in the applied spot and enters into the pores in the surface layer region, is capable of being quickly introduced toward the bottom surface side of the film-shaped hard porous body via the pores larger than the pores of the surface layer region. Therefore, the formation of the spots can be performed efficiently.
Further, in the hard macro array in accordance with the present invention, a surface of the film-shaped hard porous body, on which surface the spots are to be arrayed, should preferably be coated with an auxiliary substance for promoting fixation of the test substances to the surface of the film-shaped hard porous body. With the hard macro array in accordance with the present invention, wherein the surface of the film-shaped hard porous body is coated with the auxiliary substance, the efficiency, with which the test substances are fixed to the surface of the inorganic type of film-shaped hard porous body, can be enhanced.
The hard macro array in accordance with the present invention has a higher hardness than the hardness of the conventional macro arrays, in which polymeric organic membranes are employed as the base materials. Therefore, the hard macro array in accordance with the present invention is easy to process, and careless bending, creasing, or the like, can be prevented from occurring. Also, with the hard macro array in accordance with the present invention, the operator is capable of being released from feeling of tension and stress at the time of the operation for hybridization, autoradiography, or the like. Further, with the hard macro array in accordance with the present invention, operation characteristics can be enhanced, and therefore the processing, such as hybridization or autoradiography, is capable of being performed efficiently and smoothly.
The present invention will hereinbelow be described in further detail with reference to the accompanying drawings.